Diffusion-weighted MRI for the detection of colorectal polyps: feasibility study

The purpose of this study was to determine the feasibility of diffusion-weighted magnetic resonance imaging (DWI) for detecting colorectal polyps. DWI (high b-value of 1000 s/mm²) was prospectively performed in 26 symptomatic patients who were scheduled to undergo colonoscopy. DWI and colonoscopic findings were interpreted in a blinded manner. The sensitivity and positive predictive value (PPV) of DWI for the detection of clinically relevant polyps (≥ 6 mm) and colorectal cancer (CRC) were calculated on a per-lesion basis, using colonoscopy results as the standard of reference. Sensitivity, specificity, PPV and negative predictive value (NPV) on a per-patient basis were also calculated. Sensitivity and PPV on a per-lesion basis were 80.0% [95% confidence interval (CI): 49.0%–94.3%] and 72.7% (95% CI: 43.4%–90.3%) for polyps ≥ 6 mm and CRC. Sensitivity, specificity, PPV and NPV on a per-patient basis were 85.7% (95% CI: 48.7%–97.4%), 84.2% (95% CI: 62.4%–94.5%), 66.7% (95% CI: 35.4%–87.9%) and 94.1% (95% CI: 73.0%–99.0%) for polyps ≥ 6mm and CRC. In conclusion, DWI cannot yet be recommended in a clinical setting in which DWI is performed first and subsequent colonoscopy is only performed in patients with positive findings at DWI. Further (technical) developments are required to increase its diagnostic yield.     

Laser cleaning of steel for paint removal

Paint removal is an important part of steel processing for marine and offshore engineering. For centuries, a blasting techniques have been widely used for this surface preparation purpose. But conventional blasting always has intrinsic problems, such as noise, explosion risk, contaminant particles, vibration, and dust. In addition, processing wastes often cause environmental problems. In recent years, laser cleaning has attracted much research effort for its significant advantages, such as precise treatment, and high selectivity and flexibility in comparison with conventional cleaning techniques. In the present study, we use this environmentally friendly technique to overcome the problems of conventional blasting. Processed samples are examined with optical microscopes and other surface characterization tools. Experimental results show that laser cleaning can be a good alternative candidate to conventional blasting.     

The effects of radiofrequency fields on cell proliferation are non-thermal

The number of reports on the effects induced by radiofrequency (RF) electromagnetic fields and microwave (MW) radiation in various cellular systems is still increasing. Until now no satisfactory mechanism has been proposed to explain the biological effects of these fields. One of the current theories is that heat generation by RF/MW is the cause, in spite of the fact that a great number of studies under isothermal conditions have reported significant cellular changes after exposure to RF/MW. Therefore, this study was undertaken to investigate which effect MW radiation from these fields in combination with a significant change of temperature could have on cell proliferation. The experiments were performed on the same cell line, and with the same exposure system as in a previous work [S. Kwee, P. Raskmark, Changes in cell proliferation due to environmental non-ionizing radiation: 2. Microwave radiation, Bioelectrochem. Bioenerg., 44 (1998), pp. 251-255]. The field was generated by signal simulation of the Global System for Mobile communications (GSM) of 960 MHz. Cell cultures, growing in microtiter plates, were exposed in a specially constructed chamber, a Transverse Electromagnetic (TEM) cell. The Specific Absorption Rate (SAR) value for each cell well was calculated for this exposure system. However, in this study the cells were exposed to the field at a higher or lower temperature than the temperature in the field-free incubator i.e., the temperature in the TEM cell was either 39 or 35 +/- 0.1 degrees C. The corresponding sham experiments were performed under exactly the same experimental conditions. The results showed that there was a significant change in cell proliferation in the exposed cells in comparison to the non-exposed (control) cells at both temperatures. On the other hand, no significant change in proliferation rate was found in the sham-exposed cells at both temperatures. This shows that biological effects due to RF/MW cannot be attributed only to a change of temperature. Since the RF/MW induced changes were of the same order of magnitude at both temperatures and also comparable to our previous results under isothermal conditions at 37 degrees C, cellular stress caused by electromagnetic fields could initiate the changes in cell cycle reaction rates. It is widely accepted that certain classes of heat-shock proteins are involved in these stress reactions.     

Prospectives of the hadron program in ATLAS

One of the first measurements that will be made at the LHC by ATLAS deals with the properties of inelastic collisions,namely the central charged particle density and transverse momentum distributions.Current predictions of these distributions have large uncertainties in the LHC energy range.We describe the ATLAS minimum bias triggers,designed to seleet all kind of inelastic interactions,and the performance of the track reconstruction software which was adapted to soft particle track reconstruction.The precision with which the minimum bias distributions can be measured with early data is presented and the uncertainties on the inelastic distributions due to trigger bias is discussed.     

Plasmonic Liquid Marbles: A Miniature Substrate‐less SERS Platform for Quantitative and Multiplex Ultratrace Molecular Detection

Inspired by aphids, liquid marbles have been studied extensively and have found application as isolated microreactors, as micropumps, and in sensing. However, current liquid‐marble‐based sensing methodologies are limited to qualitative colorimetry‐based detection. Herein we describe the fabrication of a plasmonic liquid marble as a substrate‐less analytical platform which, when coupled with ultrasensitive SERS, enables simultaneous multiplex quantification and the identification of ultratrace analytes across separate phases. Our plasmonic liquid marble demonstrates excellent mechanical stability and is suitable for the quantitative examination of ultratrace analytes, with detection limits as low as 0.3 fmol, which corresponds to an analytical enhancement factor of 5×10⁸. The results of our simultaneous detection scheme based on plasmonic liquid marbles and an aqueous–solid–organic interface quantitatively tally with those found for the individual detection of methylene blue and coumarin.     

Modulating Orientational Order to Organize Polyhedral Nanoparticles into Plastic Crystals and Uniform Metacrystals

In nanoparticle self-assembly, the current lack of strategy to modulate orientational order creates challenges in isolating large-area plastic crystals. Here, we achieve two orientationally distinct supercrystals using one nanoparticle shape, including plastic crystals and uniform metacrystals. Our approach integrates multi-faceted Archimedean polyhedra with molecular-level surface polymeric interactions to tune nanoparticle orientational order during self-assembly. Experiments and simulations show that coiled surface polymer chains limit interparticle interactions, creating various geometrical configurations among Archimedean polyhedra to form plastic crystals. In contrast, brush-like polymer chains enable molecular interdigitation between neighboring particles, favoring consistent particle configurations and result in uniform metacrystals. Our strategy enhances supercrystal diversity for polyhedra comprising multiple nondegenerate facets.     

Injection-locked single-frequency laser with an output power of?220?W

A solid-state laser system for the next generation of gravitational wave detectors with an output power of 220?W at the wavelength of 1064?nm is presented. Single-frequency operation of the laser was achieved by injection-locking of a high-power ring oscillator to an amplified non-planar ring oscillator (NPRO) following the Pound?CDrever?CHall scheme. The high-power stage which features four longitudinally pumped Nd:YAG laser crystals as active media in a ring resonator configuration was designed for reliable long term operation. Using a non-confocal ring cavity to filter the output beam, a pure TEM₀₀ mode with 168 W output power was obtained.     

Heterogeneity of regional cerebral glucose metabolism demonstrated in situ in rat brain by 19F NMR rotating frame zeugmatography: one dimensional chemical shift imaging of normal and gliosarcoma implanted brain

Using 19-fluorine (19F) as nuclear magnetic resonance (NMR) signal probe and 2-fluoro-2-deoxy-D-glucose (2-FDG) as metabolic probe, one dimensional "imaging" (metabolite mapping) of pathway specific glucose metabolism in the pentose monophosphate shunt (PMS) and aldose reductase sorbitol (ARS) pathways were performed in situ in rat brain utilizing one dimensional rotating frame zeugmatography. Normal brain showed highest PMS activities in the brainstem consonant with known spatially heterogeneous concentration of glucose-6-phosphate dehydrogenase, the rate limiting enzyme for the PMS. The brain harboring sufficiently large gliosarcoma in the cerebrum showed a higher PMS/ARS area ratio indicating higher PMS activities in tumor which was localized by zeugmatography. The present study demonstrated the feasibility of studying regional glucose metabolism in the PMS and ARS utilizing 2-FDG.     

SERS- and Electrochemically Active 3D Plasmonic Liquid Marbles for Molecular-Level Spectroelectrochemical Investigation of Microliter Reactions

Liquid marbles are emergent microreactors owing to their isolated environment and the flexibility of materials used. Plasmonic liquid marbles (PLMs) are demonstrated as the smallest spectroelectrochemical microliter-scale reactor for concurrent spectro- and electrochemical analyses. The three-dimensional Ag shell of PLMs are exploited as a bifunctional surface-enhanced Raman scattering (SERS) platform and working electrode for redox process modulation. The combination of SERS and electrochemistry (EC) capabilities enables in situ molecular read-out of transient electrochemical species, and elucidate the potential-dependent and multi-step reaction dynamics. The 3D configuration of our PLM-based EC-SERS system exhibits 2-fold and 10-fold superior electrochemical and SERS performance than conventional 2D platforms. The rich molecular-level electrochemical insights and excellent EC-SERS capabilities offered by our 3D spectroelectrochemical system are pertinent in charge transfer processes.